Artificial limbs, including leg prostheses, employ a wide range of technologies to provide solutions suitable to many differing needs. For a trans-femoral amputee, basic needs in a leg prosthesis include stability, both while standing and during the stance phase of a walking gait, and mechanical compatibility with the walking (or running) gait, and some manner of knee flexion during stance and swing phases of a gait. Certain tradeoffs exist between security and stability and walking or running performance (dynamic behavior).
A simple, non-articulable leg prosthesis (having no movable knee) may provide maximum stability but does not provide for an ideal gait. Also, sitting may be awkward if a person cannot bend his knee. Available articulating prosthetic knees provide improved walking or running performance but are lacking in stability and control. They are also mechanically complex, expensive, or both. This can be especially problematic for low activity users, such as elderly or fresh amputees not yet very skilled in controlling the knee.
The amount of control or stability required can vary from user to user, while known prosthetic knees have no adjustability.
There is a need for a prosthetic knee that provides stability in stance and simulates more natural knee movement in swing.